Unit 1 CSA Code

A Painter object called myPainter is facing north. Consider the following code segment.

while (!myPainter.isFacingSouth()) {

myPainter.turnLeft();

}

myPainter.turnLeft();

The effect of this code is that the myPainter object is now:

• facing north

• facing east

• facing west

• facing south

Answer explanation

This code runs you will turnLeft until you face south. Once you face south you will turnLeft 1 time in this example. This means you will face east.

Which of the following is a TRUE statement about constructors in Java?

• The constructor contains all of the methods that an object can utilize.

• The constructor is used to create objects of a class.

• The constructor should not have the same name as the class.

• In inheritance, the parent class should always contain the keyword super.

A Painter object called myPainter is initially facing east. Consider the following code segment.

while (myPainter.canMove()) {

myPainter.move(); }

After the loop has terminated, which of the following MUST be true?

• The Painter object is blocked from moving north.

• The Painter object is blocked from moving south.

• The Painter object is blocked from moving east.

• The Painter object will crash into an object or wall.

Answer explanation

When painter can move it will continue until it runs into a wall

Which of the following are inherited when one class extends another?

I. private attributes

II. public constructors

III. public methods

•   II and III

• I and II

• III only

• I only

Consider the following class headers.

public class Food { //implementation not shown }

public class Dessert extends Food { //implementation not shown }

public class Cookie extends Dessert { //implementation not shown }

Which statement below is true regarding the class declarations?

I. Food is a subclass of Cookie

II. Dessert is a superclass of Cookie

III. Cookie is a subclass of Dessert

IV. Cookie is a superclass of Food

• II and III

• II and IV

• I and II

• III only

Which of the following evaluates to false?

I. true

II. !true

III. false

IV. !false

• III and IV

• II and III

• I and IV

• III only